Module: DeclarativeCache

Defined in:
lib/ruby_ext/declarative_cache.rb

Constant Summary collapse

DISABLED = 
false

Class Method Summary collapse

Class Method Details

.cache_method(klass, *methods) ⇒ Object 



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# File 'lib/ruby_ext/declarative_cache.rb', line 28

def cache_method klass, *methods
  methods.each do |method|
    klass.class_eval do
      als = "cached_#{escape_method(method)}"
      iv_check = "@#{als}_check"
      iv = "@#{als}"
    
      raise "Can't cache the #{method} twice!" if instance_methods.include?(als)
      
      alias_method als, method
      
      define_method method do |*args|
        raise "You tried to use cache without params for method with params (use 'cache_method_with_params' instead)!" unless args.empty?
        unless cached = instance_variable_get(iv)
          unless check = instance_variable_get(iv_check)
            cached = send als
            instance_variable_set iv, cached
            instance_variable_set iv_check, true
          end
        end
        cached
      end
    end
  end
end

.cache_method_with_params(klass, *methods) ⇒ Object 



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# File 'lib/ruby_ext/declarative_cache.rb', line 54

def cache_method_with_params klass, *methods        
  methods.each do |method|  
    klass.class_eval do      
      als = "cached_#{escape_method(method)}"
      iv = "@#{als}"
      
      raise "Can't cache the '#{method}' twice!" if instance_methods.include?(als)
      
      alias_method als, method
              
      define_method method do |*args| 
        unless results = instance_variable_get(iv)
          results = Hash.new(NotDefined)
          instance_variable_set iv, results
        end
        
        result = results[args]
                  
        if result.equal? NotDefined 
          result = send als, *args
          results[args] = result
        end
      
        result
      end
    end
  end
end